In this paper, we investigate the links between the flooding paradigm and the topological watershed. Guided by the analysis of a classical flooding algorithm, we present several notions that lead us to a better understanding of the watershed: minima extension, mosaic, pass value and separation. We first make a detailed examination of the effectiveness of the divide set produced by watershed alg...

Watershed transform is a key operator in video segmentation algorithms. However, the computation load of watershed transform is too large for real-time applications. In this paper, a new fast watershed algorithm, named P-Watershed, for image sequence segmentation is proposed. By utilizing the temporal coherence property of the video signal, this algorithm updates watersheds instead of searching...

The relationship between some habitat factors and fish assemblage was analyzed in the Taleghan River, Alborz Province, Iran. Fish specimens from thirty-three sites were sampled by electrofishing device in October 2014. The habitat parameters, including elevation (m), water depth (cm), river width (m), river slope (%), current velocity (m.s-1), number of large stone (> 15 cm), average stone diam...

Among the structural and non-structural methods of flood control, rockfill dams are a kind of detention structures that increase travel time and reduce the maximum instantaneous flood discharge. Due to the rapid and automatic effect of these dams, flood reduction happens more quickly. In this research, the best arrangement of rockfill dams at Taleghan basin was determined based on the cost of r...

This paper is an overview of this special issue devoted to watershed research in Acadia National Park (Acadia NP). The papers address components of an integrated research program on two upland watersheds at Acadia NP, USA (44 degrees 20' N latitude; 68 degrees 15' E longitude). These watersheds were instrumented in 1998 to provide a long-term foundation for regional ecological and watershed res...

The shrinking Baiyangdian Lake and drying up rivers are widely observed in recent years. Due to the significant advantages in integrated analyses of natural and economic systems, emergy analysis is introduced in this paper to assess the health status of Baiyangdian Watershed. First, we establish a emergy based conceptual framework for the assessment, delineate an emergy flow diagram of Baiyangd...

In fall (November 2005) and winter (February 2006), we collected current-year foliage of native red spruce (Picea rubens Sarg.) growing in a reference watershed and in a watershed treated in 1999 with wollastonite (CaSiO(3), a slow-release calcium source) to simulate preindustrial soil calcium concentrations (Ca-addition watershed) at the Hubbard Brook Experimental Forest (Thornton, NH). We ana...

4 Watershed modeling requires accurate estimates of precipitation, however in some cases 5 it is necessary to simulate streamflow in a watershed for which there is no precipitation gauge 6 records within close proximity to the watershed. For such cases, we propose an approach for 7 estimating watershed-scale precipitation by combining (or fusing) gauge-based precipitation 8 time series with rad...

The distribution and movement of arsenic was investigated on the Aberjona watershed in eastern Massachusetts for the purpose of identifying where and by what processes present and past human exposures to this element could have occurred. It was found that although most of the arsenic was originally released in the headwaters of the watershed, extensive migration had occurred, and the potential ...

[1] Watershed-scale water quality models involve substantial uncertainty in model output because of sparse water quality observations and other sources of uncertainty. Assessing the uncertainty is very important for those who use the models to support management decision making. Systematic uncertainty analysis for these models has rarely been done and remains a major challenge. This study aimed...